For various reasons, it is often desirable to reduce the nicotine content of tobacco. For example, in recent years, low nicotine content "mild" cigarettes have gained substantial consumer acceptance.
There are numerous techniques available for reducing the nicotine content of tobacco. However, most of these techniques result in the removal of other tobacco ingredients along with the nicotine. The removal of other ingredients adversely affects desirable flavor and taste properties, or other desirable smoking qualities. Thus, there is a need for techniques which are effective to selectively reduce the nicotine content of tobacco without deleteriously modifying its desirable smoking properties.
Processes for the reduction of the nicotine content of tobacco by microbial treatment are disclosed in copending applications Ser. No. 632,804 filed Nov. 17, 1975, by Geiss, et al. and Ser. No. 632,863 filed Nov. 17, 1975, by Newton, et al.
The microbial treatments of these copending applications, which are incorporated herein by reference, involve the use of microorganism cultures which are specific to nicotine whereby the nicotine content of tobacco may be substantially reduced without producing any substantial effect on other components of the tobacco. While the nicotine content of tobacco is reduced by these processes, the organoleptic properties attributed to smoke generated from the tobacco are generally maintained. However, after treatment, a milder smoke is produced.
The process of the present invention provides a technique for maximizing the growth and nicotine degrading activity of microorganisms useful for treating tobacco to reduce the nicotine content thereof. The microorganisms suitable for use in the present invention are those which degrade nicotine through a biochemical reaction in which 3-succinoylpyridine, as well as 6-hydroxy-3-succinoylpyridine and other by-products, are formed. After cultures of the microorganisms are prepared in accordance with the process of the present invention, they may be employed to reduce the nicotine content of tobacco by inoculating tobacco with the cultures under proper conditions of temperature, moisture and pH.